Here's an interesting rabbit hole from Trace Evidence:
TL;DR - a young college student lived several hours away from his family in California, and one day during break, he drove to his parents house but never made it there. Along the way, his parents called numerous times, but he would give weird answers and would just sit there in his car without moving. His parents called the police to check up on him, and he just sat there in his car parked along the road, refusing to move. Eventually several hours later he started driving again, but never made it to his destination. The police did a search and found his SUV flipped on its side within the woods, but no trace of him could be found. Also they spoke with his friends, and found out that before he drove to his parents' house, he sold a bunch of his expensive electronics as if he planned on never returning. Since the disappearance, there have been rumors of sightings of him among groups of homeless people in the Pacific Northwest.
The main theory is that he was secretly depressed and suicidal, and planned to visit his parents one last time before committing suicide. On his trip to his parents, he kept parking his car to contemplate suicide, and wasn't sure if he wanted to go through with it. He might have tried to drive his car off a cliff, but bailed out, and the car flipped over. Then perhaps he got injured in the accident and staggered away, either dying from the elements or drifting into a city to become a homeless person with amnesia from the car accident.